package cn.hh.wechatkit.util;

import cn.hh.wechatkit.data.postdata.card.EncryptCodePostData;
import cn.hh.wechatkit.data.returndata.card.meta_RDate_DecodeCardCode;
import cn.hh.wechatkit.exception.Wx_Exception_InvalidParam;
import cn.hh.wechatkit.exception.Wx_Exception_InvalidResponse;
import cn.hh.wechatkit.helper.CacheHelper;
import cn.hh.wechatkit.pojo.user.Wx_UnionInfo;
import cn.hhchat.kit.http.httpUtil;
import com.alibaba.fastjson.JSON;
import okhttp3.Response;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.codehaus.xfire.util.Base64;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.io.IOException;
import java.security.AlgorithmParameters;
import java.security.Security;
import java.util.Arrays;

import static cn.hh.wechatkit.helper.WxConst.DecodeCardCode_POST_URL;

/**
 * Created this one by HMH on 2018/9/6.
 */
public class WxAppDecodeUtil {

    public static Wx_UnionInfo getUserInfo(String encryptedData, String sessionKey, String iv){
        // 被加密的数据
        byte[] dataByte = Base64.decode(encryptedData);
        // 加密秘钥
        byte[] keyByte = Base64.decode(sessionKey);
        // 偏移量
        byte[] ivByte = Base64.decode(iv);
        try {
            // 如果密钥不足16位，那么就补足.  这个if 中的内容很重要
            int base = 16;
            if (keyByte.length % base != 0) {
                int groups = keyByte.length / base + (keyByte.length % base != 0 ? 1 : 0);
                byte[] temp = new byte[groups * base];
                Arrays.fill(temp, (byte) 0);
                System.arraycopy(keyByte, 0, temp, 0, keyByte.length);
                keyByte = temp;
            }
            // 初始化
            Security.addProvider(new BouncyCastleProvider());
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding","BC");
            SecretKeySpec spec = new SecretKeySpec(keyByte, "AES");
            AlgorithmParameters parameters = AlgorithmParameters.getInstance("AES");
            parameters.init(new IvParameterSpec(ivByte));
            cipher.init(Cipher.DECRYPT_MODE, spec, parameters);// 初始化
            byte[] resultByte = cipher.doFinal(dataByte);
            if (null != resultByte && resultByte.length > 0) {
                String result = new String(resultByte, "UTF-8");
                return JSON.parseObject(result, Wx_UnionInfo.class);
            }
        } catch (Exception e ){
            throw new Wx_Exception_InvalidParam(e);
        }
        return null;
    }

    public String decodeCode(String encryptCode) throws IOException {
        String url = DecodeCardCode_POST_URL.replace("ACCESS_TOKEN", CacheHelper.getAccessToken().getAccess_token());
        EncryptCodePostData encryptCodePostData = new EncryptCodePostData(encryptCode);
        Response response = httpUtil.postJson(url, encryptCodePostData);
        //获取数据
        if (response != null) {
            String body = response.body().string();
            meta_RDate_DecodeCardCode meta_rDate_decodeCardCode =  JSON.parseObject(body, meta_RDate_DecodeCardCode.class);
            if(meta_rDate_decodeCardCode == null) {
                throw new Wx_Exception_InvalidParam("解析失败");
            }
            if(meta_rDate_decodeCardCode.getErrcode() != 0) {
                throw new Wx_Exception_InvalidParam("解析失败" + meta_rDate_decodeCardCode.getErrmsg());
            }
            return meta_rDate_decodeCardCode.getCode();
        }
        throw new Wx_Exception_InvalidResponse("没有收到响应，或者请求出错");
    }
}
